MECHANISM OF ANTIBODY FORMATION 73 



of parts of the surface films of these cells, both normal globulin and 

 antibody globulin are carried out into the blood plasma. Thus it is 

 stated that these mononuclear cells, functioning first as macrophages 

 ("big eater"), render the antigen into suitable soluble form within 

 the vacuole, and then as clasmatocytes ("shedding of exoplasm") in- 

 corporate it into the cytoplasm, and there in some way the increase 

 in the synthesis of normal globulin and the modification of some of 

 it into antibody globulin take place. 



Coupling highly indiffusible blue dye T-1824, Evans blue, with 

 various serum proteins and egg albumin, Kruse and McMaster (1949) 

 prepared intensely blue dye-azo-proteins. A similar antigen consisting 

 of extremely diffusible dye, echt-saure-blau, and of bovine y-globulin 

 was also prepared. 



On intraperitoneal or intravenous injections, the azoproteins ap- 

 peared in the Kupffer cells of the liver and sinus and reticular cells in 

 lymph nodes, especially the great mesenteric node. These cells were 

 particularly active in the removal of the blue antigens from the blood, 

 but many other reticulo-endothelial cells were found to be active to 

 a lesser degree. The storage of the antigenic material was observed in 

 the cytoplasm only; it was not observed within nuclei, nor was it 

 observed within the brain cells. Blue color was seen in the reticulo- 

 endothelial cells of mice as long as 3Vi months after injecting echt- 

 saure-blau azoglobulin. The seizure of the blue azoprotein by reticulo- 

 endothelial cells almost everywhere in the body was interpreted to 

 indicate that antigenic stimuls to antibody formation can be brought to 

 bear from practically all parts of the body upon those tissues or cells 

 that are capable of antibody formation. 



b. Plasma Cells as Antibody Producers. The hypothesis that 

 plasma cells might be associated with process of immunization has been 

 advanced by many authors on the basis of pathological-anatomical 

 observations. In sternal bone-marrow punctures, a proliferation of 

 plasma cells in lesions associated with hyperglobulinemia (infections, 

 agranulocytosis, serum sickness and other morbid conditions) has been 

 considered as affording clinical evidence in support of the hypothesis 

 that plasma cells function as antibody producers. 



Plasma. Cells QPlasmocyte, Phagocytes^. The plasma cell is described 

 to be a cell rich in protoplasm, with eccentrically placed nucleus, 

 relatively small, round or oval, with five to eight bands of chromatin 



